Tipped carbon pencil for dry cells



Mar. 3, 1925- N. DAX

TTPPED CARBON PENCIL FOR DRY CELLS Filed Jun 30, 1923 INVENTOR. Min 1 BY 7 14? fWM ATTGRNEX Patented Mar. 3, 1925. A 7

UNITED STATES PATENT OFFICE.

NICHOLAS DAX, OF DUNDEE, ILLINOIS, ASSIGNOR OF ONE-HALF TO OT'IO GRAENING,

O'F DUNDEE, ILLINOIS.

TIPPED CARBON PENCIL FOR DRY CELLS.

Application filed June 30, 1923.

T 0 all whom it may concern:

Be it known that I, NICHOLAS DAX, a citizen of the United States, residing at Dundee, county of Kane, State of Illinois, have invented a certain new and useful Improvement in Tipped Carbon Pencils for Dry Cells, and declare the following to be a full, clear, and exact description of the same, such as will enable others skilled in the art to which it pertains to make and use the same, reference being had to the accompanying drawing, which forms a part of this specification.

Carbon pencils for dry cell batteries must be provided with metal tips to permit good electrical contact to be made between the same and conductors connected therewith. It is now the custom to press sheet metal caps, usually made of brass, on the ends of the pencils, for this purpose. It is evident that the pencils themselves and the caps must be accurately made in order to secure a good fit of the caps on the pencils. This is particularly true in the cases of small pencils having a diameter of a quarter of an inch or less. The result is that the carbon pencils themselves are more expensive than they would be if they were made accurate only within limits sufficient to meet the other requirements of the uses to which they are put: the caps themselves are comparatively expensive: and the operation of assembling the caps on the pencils, including the unavoidable losses due to breakage, is expensive. Furthermore, in order to produce a good electrical connection with one of the brass caps as, for example, when a wire is to be soldered thereto, it is necessary to clean the same to secure a bright metallic surface.

The object of the present invention is to produce a simple and novel tipped carbon pencil which will make unnecessary the extreme accuracy of diameter which has heretofore been required to permit the application thereto of a metal cap; in which the tip will be produced by a simple, inexpensive process: and which will permit a wire or other conductor to be soldered thereto without preliminary cleaning of the tip.

The various features of novelty whereby my invention is characterized will hereinafter be pointed out with particularity in the Serial No. 648,653.

claims; but for a full understanding of my invention and of its objects and advantages, reference may be had to the following detailed description taken in connection with the accompanying drawing, wherein:

Figure 1 is a side view of a carbon pencil before being tipped; Fig. 2 is a View similar to Fig. 1, showing the condition of the pen cil after one end has been .copper plated; Fig. 3 is a view similar to Figs. 1 and 2, showing the completed pencil; and Fig. 4 is an elevation of the pencil having a wire soldered thereto.

Referring to the drawing, 1 represents a carbon pencil of any usual or suitable size and shape, the same being ordinarily in the form of a cylinder. In forming the tip, I first produce a copper coating 2, by an electroplating process, on one end of the pen oil and then, on the extreme plated end, I add a thin layer 3 of tin or solder in any usual or suitable way for applying this metal. When a wire 4 is to be connected to the pencil, it is simply laid upon the tin or solder on the pencil and is attached thereto by means of a drop 5 of solder. In applying the drop of solder, it is unnecessary first to clean the end of the pencil, because the heat of the soldering iron will partially melt the tip and cause the molten drop that is applied thereto to be fused into an integral body therewith.

It will thus be seen that I have done away with tips in the form of preformed caps, and with the need for making the carbon pencils more accurately than is required by the uses to which they are to be put, the tip ping process being an inexpensive one; so that tipped carbon pencils may be made more cheaply than heretofore. Furthermore, it is more convenient electrically to connect conductors to my improved pencils than it has heretofore been and, at the same time, there is greater certainty that the connections will be perfect.

While I have illustrated and described with particularity only a single preferred form of my invention, I do not desire to be limited to the exact structural details thus illustrated and described; but intend to cover all forms and arrangements which come within the terms employed in the defi nitions of my invention constituting the copper-plated and a tip of metal, fusible at appended claim, the term solder being used the temperature of a solder employed to to cover tin, or any usual or suitable solsecure a conductor to said tip, adhering to dering metal. the copper plating. 5 I claim: In testimony whereof, I sign this specifi- An article of manufacture comprising a cation. carbon pencil for dry cells having an end NICHOLAS DAX. 

